The Pluripotent Activities of Caffeic Acid Phenethyl Ester

Encapsulation of caffeic acid phenethyl ester by self-assembled sorghum peptide nanoparticles: Fabrication, storage stability and interaction mechanisms

Caffeic acid phenethyl ester (CAPE) is a naturally occurring phenolic compound with various biological activities. However, poor water solubility and storage stability limit its application. In this context, sorghum peptides were used to encapsulate CAPE. Sorghum peptides could self-assemble into regularly spherical nanoparticles (SPNs) by hydrophobic interaction and hydrogen bonds. Solubility of encapsulated CAPE was greatly increased, with 9.44 times higher than unencapsulated CAPE in water. Moreover, the storage stability of CAPE in aqueous solution was significantly improved by SPNs encapsulation. In vitro release study indicated that SPNs were able to delay CAPE release during the process of gastrointestinal digestion. Besides, fluorescence quenching analysis showed that a static quenching existed between SPNs and CAPE. The interaction between CAPE and SPNs occurred spontaneously, mainly driven by hydrophobic interactions. The above results suggested that SPNs encapsulation was an effective approach to improve the water solubility and storage stability of CAPE.

Caffeic acid phenethyl ester promotes oxaliplatin sensitization in colon cancer by inhibiting autophagy

Colon cancer ranks as the third most prevalent form of cancer globally, with chemotherapy remaining the primary treatment modality. To mitigate drug resistance and minimize adverse effects associated with chemotherapy, selection of appropriate adjuvants assumes paramount importance. Caffeic acid phenethyl ester (CAPE), a naturally occurring compound derived from propolis, exhibits a diverse array of biological activities. We observed that the addition of CAPE significantly augmented the drug sensitivity of colon cancer cells to oxaliplatin. In SW480 and HCT116 cells, oxaliplatin combined with 10 µM CAPE reduced the IC50 of oxaliplatin from 14.24 ± 1.03 and 84.16 ± 3.02 µM to 2.11 ± 0.15 and 3.92 ± 0.17 µM, respectively. We then used proteomics to detect differentially expressed proteins in CAPE-treated SW480 cells and found that the main proteins showing changes in expression after CAPE treatment were p62 (SQSTM1) and LC3B (MAP1LC3B). Gene ontology analysis revealed that CAPE exerted antitumor and chemotherapy-sensitization effects through the autophagy pathway. We subsequently verified the differentially expressed proteins using immunoblotting. Simultaneously, the autophagy inhibitor bafilomycin A1 and the mCherry-EGFP-LC3 reporter gene were used as controls to detect the effect of CAPE on autophagy levels. Collectively, the results indicate that CAPE may exert antitumor and chemotherapy-sensitizing effects by inhibiting autophagy, offering novel insights for the development of potential chemosensitizing agents.

Caffeic acid phenethyl ester derivative exerts remarkable anti-hepatocellular carcinoma effect, non-inferior to sorafenib, in vivo analysis

Caffeic acid phenethyl ester (CAPE) and its derivatives exhibit considerable effects against hepatocellular carcinoma (HCC), with unquestioned safety. Here we investigated CAPE derivative 1' (CAPE 1') monotherapy to HCC, compared with sorafenib. HCC Bel-7402 cells were treated with CAPE 1', the IC50 was detected using CCK-8 analysis, and acute toxicity testing (5 g/kg) was performed to evaluate safety. In vivo, tumor growth after CAPE 1' treatment was evaluated using an subcutaneous tumor xenograft model. Five groups were examined, with group 1 given vehicle solution, groups 2, 3, and 4 given CAPE 1' (20, 50, and 100 mg/kg/day, respectively), and group 5 given sorafenib (30 mg/kg/day). Tumor volume growth and tumor volume-to-weight ratio were calculated and statistically analyzed. An estimated IC50 was 5.6 µM. Acute toxicity tests revealed no animal death or visible adverse effects with dosage up to 5 g/kg. Compared to negative controls, CAPE 1' treatment led to significantly slower increases of tumor volume and tumor volume-to-weight. CAPE 1' and sorafenib exerted similar inhibitory effects on HCC tumors. CAPE 1' was non-inferior to sorafenib for HCC treatment, both in vitro and in vivo. It has great potential as a promising drug for HCC, based on effectiveness and safety profile.

The neuroprotective effects of caffeic acid phenethyl ester against methamphetamine-induced neurotoxicity

Methamphetamine (METH) is a highly abused substance on a global scale and has the capacity to elicit toxicity within the central nervous system. The neurotoxicity induced by METH encompasses neuronal degeneration and cellular demise within the substantia nigra-striatum and hippocampus. Caffeic acid phenethyl ester (CAPE), a constituent of propolis, is a diminutive compound that demonstrates antioxidative and anti-inflammatory characteristics. Numerous investigations have demonstrated the safeguarding effects of CAPE in various neurodegenerative ailments. Our hypothesis posits that CAPE may exert a neuroprotective influence on METH-induced neurotoxicity via specific mechanisms. In order to validate the hypothesis, a series of experimental techniques including behavioral tests, immunofluorescence labeling, RNA sequencing, and western blotting were employed to investigate the neurotoxic effects of METH and the potential protective effects of CAPE. The results of our study demonstrate that CAPE effectively ameliorates cognitive memory deficits and anxiety symptoms induced by METH in mice. Furthermore, CAPE has been observed to attenuate the upregulation of neurotoxicity-associated proteins that are induced by METH exposure and also reduced the loss of hippocampal neurons in mice. Moreover, transcriptomics analysis was conducted to determine alterations in gene expression within the hippocampus of mice. Subsequently, bioinformatics analysis was employed to investigate the divergent outcomes and identify potential key genes. Interferon-stimulated gene 15 (ISG15) was successfully identified and confirmed through RT-qPCR, western blotting, and immunofluorescence techniques. Our research findings unequivocally demonstrated the neuroprotective effect of CAPE against METH-induced neurotoxicity, with ISG15 may have an important role in the underlying protective mechanism. These results offer novel perspectives on the treatment of METH-induced neurotoxicity.

Plant phenolics inhibit focal adhesion kinase and suppress host cell invasion by uropathogenic Escherichia coli

Traditional folk treatments for the prevention and management of urinary tract infections (UTIs) and other infectious diseases often include plants and plant extracts that are rich in phenolic compounds. These have been ascribed a variety of activities, including inhibition of bacterial interactions with host cells. Here, we tested a panel of four well-studied phenolic compounds-caffeic acid phenethyl ester (CAPE), resveratrol, catechin, and epigallocatechin gallate-for the effects on host cell adherence and invasion by uropathogenic Escherichia coli (UPEC). These bacteria, which are the leading cause of UTIs, can bind and subsequently invade bladder epithelial cells via an actin-dependent process. Intracellular UPEC reservoirs within the bladder are often protected from antibiotics and host defenses and likely contribute to the development of chronic and recurrent infections. In cell culture-based assays, only resveratrol had a notable negative effect on UPEC adherence to bladder cells. However, both CAPE and resveratrol significantly inhibited UPEC entry into the host cells, coordinate with attenuated phosphorylation of the host actin regulator Focal Adhesion Kinase (FAK or PTK2) and marked increases in the numbers of focal adhesion structures. We further show that the intravesical delivery of resveratrol inhibits UPEC infiltration of the bladder mucosa in a murine UTI model and that resveratrol and CAPE can disrupt the ability of other invasive pathogens to enter host cells. Together, these results highlight the therapeutic potential of molecules like CAPE and resveratrol, which could be used to augment antibiotic treatments by restricting pathogen access to protective intracellular niches.IMPORTANCEUrinary tract infections (UTIs) are exceptionally common and increasingly difficult to treat due to the ongoing rise and spread of antibiotic-resistant pathogens. Furthermore, the primary cause of UTIs, uropathogenic Escherichia coli (UPEC), can avoid antibiotic exposure and many host defenses by invading the epithelial cells that line the bladder surface. Here, we identified two plant-derived phenolic compounds that disrupt activation of the host machinery needed for UPEC entry into bladder cells. One of these compounds, resveratrol, effectively inhibited UPEC invasion of the bladder mucosa in a mouse UTI model, and both phenolic compounds significantly reduced host cell entry by other invasive pathogens. These findings suggest that select phenolic compounds could be used to supplement existing antibacterial therapeutics by denying uropathogens shelter within host cells and tissues and help explain some of the benefits attributed to traditional plant-based medicines.

Potential of Natural Phenolic Compounds against Doxorubicin-Induced Chemobrain: Biological and Molecular Mechanisms Involved

Chemotherapy-induced cognitive impairment or "chemobrain" is a prevalent long-term complication of chemotherapy and one of the more devastating. Most of the studies performed so far to identify the cognitive dysfunctions induced by antineoplastic chemotherapies have been focused on treatment with anthracyclines, frequently administered to breast cancer patients, a population that, after treatment, shows a high possibility of long survival and, consequently, of chemobrain development. In the last few years, different possible strategies have been explored to prevent or reduce chemobrain induced by the anthracycline doxorubicin (DOX), known to promote oxidative stress and inflammation, which have been strongly implicated in the development of this brain dysfunction. Here, we have critically analyzed the results of the preclinical studies from the last few years that have evaluated the potential of phenolic compounds (PheCs), a large class of natural products able to exert powerful antioxidant and anti-inflammatory activities, in inhibiting DOX-induced chemobrain. Several PheCs belonging to different classes have been shown to be able to revert DOX-induced brain morphological damages and deficits associated with learning, memory, and exploratory behavior. We have analyzed the biological and molecular mechanisms implicated and suggested possible future perspectives in this research area.

Characterization of Secondary Metabolites of Leaf Buds from Some Species and Hybrids of Populus by Gas Chromatography Coupled with Mass Detection and Two-Dimensional High-Performance Thin-Layer Chromatography Methods with Assessment of Their Antioxidant Activity

Poplars provide medicinal raw plant materials used in pharmacy. Leaf buds are one of the herbal medicinal products collected from poplars, having anti-inflammatory and antiseptic properties, but there are no quality standards for their production and there is a need to determine their botanical sources. Therefore, the chemical compositions of the leaf buds from four species and varieties of poplars, Populus balsamifera, P. × berolinensis, P. × canadensis 'Marilandica', and P. wilsonii were investigated and compared using gas chromatography coupled with mass detection (GC-MS) and two-dimensional high-performance thin-layer chromatography (2D-HPTLC) in order to search for taxa characterized by a high content of biologically active compounds and with a diverse chemical composition that determines their therapeutic effects. The presence of 163 compounds belonging to the groups of flavonoids, phenolic acids derivatives, glycerides, and sesquiterpenes was revealed. Moreover, the conditions for the separation and identification of biologically active compounds occurring in analyzed leaf buds using 2D-HPTLC were optimized and used for metabolomic profiling of the studied poplars, enabling their fast and simple botanical identification. The total phenolic (TPC) and flavonoid (TFC) contents of examined extracts were determined and their antioxidant capacities were estimated by spectrophotometric DPPH, ABTS, and FRAP assays. Based on the analysis of phytochemicals and antioxidant activity, P. × berolinensis buds were selected as the raw plant material for medicinal purposes with the highest content of active compounds and the strongest antioxidant activity.

Caffeic acid phenethyl ester attenuates indomethacin-induced gastric ulcer in rats

Gastric ulcer is one of the most frequent gastrointestinal ailments worldwide. Indomethacin, one of the most potent NSAIDs, suffers undesirable ulcerogenic activity. Caffeic acid phenethyl ester (CAPE) has known health benefits. The current study examined the potential of CAPE to combat indomethacin-induced gastric ulcers in rats. Animals were randomized into 5 groups: control, Indomethacin (50 mg/kg) mg/kg), Indomethacin + CAPE (5 mg/kg/day), Indomethacin + CAPE (10 mg/kg), and Indomethacin + Omeprazole (30 mg/kg). CAPE prevented the rise in ulcer index, attenuated histopathological changes and preserved gastric mucin concentration. CAPE efficiently significantly prevented accumulation of malondialdehude (MDA) and prevented exhaustion of the enzymatic activities of catalase (CAT) and superoxide dismutase (SOD). Further, CAPE prevented the rise in the expression of tumor necrosis factor-α (TNF-α), cyclo-oxygenase-2 (COX-2) and nuclear factor kapp-B (NFκB). This was associated with down-regulation of Bax and up-regulation of Bcl-2 mRNA. Finally, CAPE prevented induced indomethacin-induced decrease in heat shock protein 70 (HSP70) in gastric tissues. In conclusion, CAPE possesses the ability to prevent indomethacin-induced gastric ulcer in rats. This involves, at least partially, antioxidation, anti-inflammation, anti-apoptosis and enhancement of HSP70 expression.

Evaluation of caffeic acid mucoadhesive tablets on minor recurrent aphthous stomatitis: a randomized, double-blind, placebo-controlled clinical trial

BACKGROUND

Oral aphthous stomatitis is a chronic inflammatory condition. Numerous medications have been investigated to treat the symptoms of the disease. However, these days patients prefer herbal medicines due to lower side effects. Considering the anti-inflammatory, analgesic, and anti-oxidant properties of Caffeic acid and its few side effects, the aim of this study was to assess the impact of Caffeic acid on recurrent aphthous stomatitis (RAS). investigating the effect of caffeic acid mucoadhesive tablets on the size and pain intensity of the aphthous lesions.

METHODS

in this double-blinded clinical trial study, 47 patients who met the inclusion criteria were selected by convenient sampling method. The patients were assigned to two groups randomly; the control group (placebo recipients) and the intervention group (Caffeic acid recipients). Patients were followed up for 7 days following the intervention. The diameter of the inflammatory lesion was measured in millimeters, and the pain intensity was recorded based on the VAS scale (Visual Analogue Scale). This trial was approved by the medical ethics committee of Mazandaran University of Medical Sciences (Ethical code: IR.MAZUMS.REC.1401.261) and received IRCT code of IRCT20220815055700N1on 03/09/2022.

RESULTS

the diameter of the lesion in both groups decreased over time, and there was no significant difference between the intervention and control groups, except on the fifth day when the diameter of the lesion was significantly greater in the control group (P = 0.012). From the second day, the control group's average pain intensity was significantly higher than the intervention group's pain intensity (P < 0.05).

CONCLUSIONS

when comparing mucoadhesive tablets containing Caffeic acid and placebo, the findings demonstrated that Caffeic acid has a significant efficacy in reducing aphthous lesions' diameter and pain intensity of the patients and are suggested for palliative oral aphthous lesions treatment since they showed significant anti-inflammatory and analgesic effects on recurrent aphthous stomatitis.

Natural products as pharmacological modulators of mitochondrial dysfunctions for the treatment of diabetes and its complications: An update since 2010

Diabetes, characterized as a well-known chronic metabolic syndrome, with its associated complications pose a substantial and escalating health and healthcare challenge on a global scale. Current strategies addressing diabetes are mainly symptomatic and there are fewer available curative pharmaceuticals for diabetic complications. Thus, there is an urgent need to identify novel pharmacological targets and agents. The impaired mitochondria have been associated with the etiology of diabetes and its complications, and the intervention of mitochondrial dysfunction represents an attractive breakthrough point for the treatments of diabetes and its complications. Natural products (NPs), with multicenter characteristics, multi-pharmacological activities and lower toxicity, have been caught attentions as the modulators of mitochondrial functions in the therapeutical filed of diabetes and its complications. This review mainly summarizes the recent progresses on the potential of 39 NPs and 2 plant-extracted mixtures to improve mitochondrial dysfunction against diabetes and its complications. It is expected that this work may be useful to accelerate the development of innovative drugs originated from NPs and improve upcoming therapeutics in diabetes and its complications.

Host-Guest Interactions of Caffeic Acid Phenethyl Ester with β-Cyclodextrins: Preparation, Characterization, and In Vitro Antioxidant and Antibacterial Activity

The aim of this study is to improve the solubility, chemical stability, and in vitro biological activity of caffeic acid phenethyl ester (CAPE) by forming inclusion complexes with β-cyclodextrin (β-CD) and hydroxypropyl-β-cyclodextrin (Hβ-CD) using the solvent evaporation method. The CAPE contents of the produced complexes were determined, and the complexes with the highest CAPE contents were selected for further characterization. Detailed characterization of inclusion complexes was performed by using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and electrospray ionization-mass spectrometry (ESI-MS). pH and thermal stability studies showed that both selected inclusion complexes exhibited better stability compared to free CAPE. Moreover, their antimicrobial activities were evaluated against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) for the first time. According to the broth dilution assay, complexes with the highest CAPE content (10C/β-CD and 10C/Hβ-CD) exhibited considerable growth inhibition effects against both bacteria, 31.25 μg/mL and 62.5 μg/mL, respectively; contrarily, this value for free CAPE was 500 μg/mL. Furthermore, it was determined that the in vitro antioxidant activity of the complexes increased by about two times compared to free CAPE.

Effects of caffeic acid phenethyl ester against multi-species cariogenic biofilms

Dental caries is a biofilm-related disease, widely perceived to be caused by oral ecological imbalance when cariogenic/aciduric bacteria obtain an ecological advantage. Compared with planktonic bacteria, dental plaques are difficult to remove under extracellular polymeric substance protection. In this study, the effect of caffeic acid phenethyl ester (CAPE) on a preformed cariogenic multi-species biofilm was evaluated, which was comprised of cariogenic bacteria (Streptococcus mutans), commensal bacteria (Streptococcus gordonii), and a pioneer colonizer (Actinomyces naeslundii). Our result revealed that treatment with 0.08 mg/mL CAPE reduced live S. mutans in the preformed multi-species biofilm while not significantly changing the quantification of live S. gordonii. CAPE significantly reduced the production of lactic acid, extracellular polysaccharide, and extracellular DNA and made the biofilm looser. Moreover, CAPE could promote the H2O2 production of S. gordonii and inhibit the expression of SMU.150 encoding mutacin to modulate the interaction among species in biofilms. Overall, our results suggested that CAPE could inhibit the cariogenic properties and change the microbial composition of the multi-species biofilms, indicating its application potential in dental caries prevention and management.

Plant Phenolics Inhibit Focal Adhesion Kinase and Suppress Host Cell Invasion by Uropathogenic Escherichia coli

Traditional folk treatments for the prevention and management of urinary tract infections (UTIs) and other infectious diseases often include plants and plant extracts that are rich in phenolic and polyphenolic compounds. These have been ascribed a variety of activities, including inhibition of bacterial interactions with host cells. Here we tested a panel of four well-studied phenolic compounds - caffeic acid phenethyl ester (CAPE), resveratrol, catechin, and epigallocatechin gallate - for effects on host cell adherence and invasion by uropathogenic Escherichia coli (UPEC). These bacteria, which are the leading cause of UTIs, can bind and subsequently invade bladder epithelial cells via an actin-dependent process. Intracellular UPEC reservoirs within the bladder are often protected from antibiotics and host defenses, and likely contribute to the development of chronic and recurrent infections. Using cell culture-based assays, we found that only resveratrol had a notable negative effect on UPEC adherence to bladder cells. However, both CAPE and resveratrol significantly inhibited UPEC entry into the host cells, coordinate with attenuated phosphorylation of the host actin regulator Focal Adhesion Kinase (FAK, or PTK2) and marked increases in the numbers of focal adhesion structures. We further show that the intravesical delivery of resveratrol inhibits UPEC infiltration of the bladder mucosa in a murine UTI model, and that resveratrol and CAPE can disrupt the ability of other invasive pathogens to enter host cells. Together, these results highlight the therapeutic potential of molecules like CAPE and resveratrol, which could be used to augment antibiotic treatments by restricting pathogen access to protective intracellular niches.

Caffeic acid phenethyl ester ameliorates titanium particle-induced bone loss and inflammatory reaction in a mouse acute model

With the increasing clinical application of dental and orthopedic implants, the problem of peri-implant osteolysis has attracted attention. The inflammatory response and osteoclast differentiation induced by wear particles play an important role in peri-implant bone loss. However, the treatment of peri-implant osteolysis is still lacking. In the present study, we investigated the effect of caffeic acid phenethyl ester (CAPE) on titanium particles induced bone loss in a mouse model. We found that CAPE significantly suppressed titanium particle-induced bone loss in vivo. CAPE treatment decreased ratio of nuclear factor kappa B receptor activator ligand (RANKL)/osteoprotegerin (OPG) and subsequently reduced osteoclastogenesis in the mouse model. In addition, CAPE downregulated the expression and secretion of interleukin-6 (IL-6), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) stimulated by titanium particles in vivo. In summary, we conclude that CAPE prevent the titanium particles-induced bone loss.

Caffeic acid phenethyl ester surmounts acquired resistance of AZD9291 in non-small cell lung cancer cells

Epithelial growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are the first-line therapy for EGFR mutated non-small cell lung cancer (NSCLC); however, resistance rapidly develops. The objective of this study was therefore to establish and characterize a gefitinib resistant NSCLC line (HCC827GR) and evaluate the therapeutic effects of natural products in combination with third-generation EGFR-TKI, AZD9291. The IC50 of gefitinib and AZD9291 in HCC827GR were significantly higher than those of HCC827 (p < 0.05). Furthermore, anchorage-independent colony assay indicated that HCC827GR cells were more aggressive than their predecessors. This was reflected by the gene/protein expression changes observed in HCC827GR versus HCC827 profiled by cancer drug resistance real-time polymerase chain reaction (RT-PCR) array and Western blot. Three natural products were screened and caffeic acid phenethyl ester (CAPE) exhibited the most significant combinative cytotoxic effect with AZD9291. Specifically, flow cytometry revealed that AZD9291 + CAPE considerably increased the fraction of cell in pre-G1 of the cell cycle and caspase-Glo3/7 assay showed a dramatic increase in apoptosis when compared to AZD9291 alone. Furthermore, Western blot showed significant downregulation of p-EGFR/p-AKT in HCC827GR cells treated with AZD9291 + CAPE as compared to AZD9291. Moreover, it is evident that AZD9291 + CAPE specifically resulted in a marked reduction in the protein expressions of the cell-proliferation-related genes p21, cyclin D1, and survivin. Finally, refined RT-PCR/Western blot data indicated that AZD9291 + CAPE may at least partially exert its synergistic effects via the PLK2 pathway. Together, these results suggest that CAPE is a clinically relevant compound to aid AZD9291 in treating EGFR-TKI resistant cells through modulating critical genes/proteins involved in cancer resistance/therapy.

Effects of natural products on cisplatin ototoxicity and chemotherapeutic efficacy

INTRODUCTION

Cisplatin is a very effective chemotherapeutic agent against a variety of solid tumors. Unfortunately, cisplatin causes permanent sensorineural hearing loss in at least two-thirds of patients treated. There are no FDA approved drugs to prevent this serious side effect.

AREAS COVERED

This paper reviews various natural products that ameliorate cisplatin ototoxicity. These compounds are strong antioxidants and anti-inflammatory agents. This review includes mostly preclinical studies but also discusses a few small clinical trials with natural products to minimize hearing loss from cisplatin chemotherapy in patients. The interactions of natural products with cisplatin in tumor-bearing animal models are highlighted. A number of natural products did not interfere with cisplatin anti-tumor efficacy and some agents actually potentiated cisplatin anti-tumor activity.

EXPERT OPINION

There are a number of natural products or their derivatives that show excellent protection against cisplatin ototoxicity in preclinical studies. There is a need to insure uniform standards for purity of drugs derived from natural sources and to ensure adequate pharmacokinetics and safety of these products. Natural products that protect against cisplatin ototoxicity and augment cisplatin's anti-tumor effects in multiple studies of tumor-bearing animals are most promising for advancement to clinical trials. The most promising natural products include honokiol, sulforaphane, and thymoquinone.

The Effect of Natural Substances Contained in Bee Products on Prostate Cancer in In Vitro Studies

Prostate cancer is a common cancer in men in older age groups. The WHO forecasts an increase in the incidence of prostate cancer in the coming years. Patients may not respond to treatment, and may not tolerate the side effects of chemotherapy. Compounds of natural origin have long been used in the prevention and treatment of cancer. Flavonoids obtained from natural products, e.g., propolis, are compounds with proven antibacterial and antiviral efficacy which modulate the immune response and may be useful as adjuvants in chemotherapy. The main aim of the present study was to evaluate the cytotoxic and pro-apoptotic properties of selected flavonoids on prostate cancer cells of the LNCaP line. The compounds used in this study were CAPE, curcumin (CUR), and quercetin (QUE). Mitochondrial and lysosome metabolism was assessed by the XTT-NR-SRB triple assay as well as by the fluorescent staining techniques. Staining for reactive oxygen species was performed as well. The experiment showed that each of the tested compounds has a cytotoxic effect on the LNCaP cell line. Different types of cell death were induced by the tested compounds. Apoptosis was induced by quercetin, while autophagy-specific changes were observed after using CAPE. Compounds obtained from other bee products have antiproliferative and cytotoxic activity against LNCaP prostate cancer cells.

Caffeic acid phenethyl ester suppresses metastasis of breast cancer cells by inactivating FGFR1 via MD2

BACKGROUND

Tumor metastasis is the main cause of death for breast cancer patients. Caffeic acid phenethyl ester (CAPE) has strong anti-tumor effects with very low toxicity and may be a potential candidate drug. However, the anti-metastatic effect and molecular mechanism of CAPE on breast cancer need more research.

METHODS

MCF-7 and MDA-MB-231 breast cancer cells were used here. Wound healing and Transwell assay were used for migration and invasion detection. Western blot and RT-qPCR were carried out for the epithelial-to-myofibroblast transformation (EMT) process investigation. Western blot and immunofluorescence were performed for fibroblast growth factor receptor1 (FGFR1) phosphorylation and nuclear transfer detection. Co-immunoprecipitation was used for the FGFR1/myeloid differentiation protein2 (MD2) complex investigation.

RESULTS

Our results suggested that CAPE blocks the migration, invasion, and EMT process of breast cancer cells. Mechanistically, CAPE inhibits FGFR1 phosphorylation and nuclear transfer while overexpression of FGFR1 reduces the anti-metastasis effect of CAPE. Further, we found that FGFR1 is bound to MD2, and silencing MD2 inhibits FGFR1 phosphorylation and nuclear transfer as well as cell migration and invasion.

CONCLUSION

This study illustrated that CAPE restrained FGFR1 activation and nuclear transfer through MD2/FGFR1 complex inhibition and showed good inhibitory effects on the metastasis of breast cancer cells.

Caffeic acid phenethyl ester: A review on its pharmacological importance, and its association with free radicals, COVID-19, and radiotherapy

Caffeic acid phenethyl ester (CAPE), a main active component of propolis and a flavonoid, is one of the natural products that has attracted attention in recent years. CAPE, which has many properties such as anti-cancer, anti-inflammatory, antioxidant, antibacterial and anti-fungal, has shown many pharmacological potentials, including protective effects on multiple organs. Interestingly, molecular docking studies showed the possibility of binding of CAPE with replication enzyme. In addition, it was seen that in order to increase the binding security of the replication enzyme and CAPE, modifications can be made at three sites on the CAPE molecule, which leads to the possibility of the compound working more powerfully and usefully to prevent the proliferation of cancer cells and reduce its rate. Also, it was found that CAPE has an inhibitory effect against the main protease enzyme and may be effective in the treatment of SARS-CoV-2. This review covers in detail the importance of CAPE in alternative medicine, its pharmacological value, its potential as a cancer anti-proliferative agent, its dual role in radioprotection and radiosensitization, and its use against coronavirus disease 2019 (COVID-19).

Ultrasound-assisted extraction of polyphenols from Chinese propolis

Introduction

Propolis is a beneficial bioactive food with rich polyphenols content. Nowadays, an increasing interest is attracted to the extraction of polyphenols from raw propolis. This study utilized the novel ultrasound-assisted approach for polyphenol extraction from Chinese propolis, aiming to improve its extraction yield and reveal the relevant mechanisms via extraction kinetic study as well as the compositional and structural analysis.

Methods

The optimum ultrasound-assisted extraction conditions were optimized according to the total phenolic content and total flavonoids content. Compositional and structural analysis were conducted using high performance liquid chromatography-quadrupole-time of flight tandem mass spectrometry, high-performance liquid chromatography, Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscope (SEM).

Results and discussion

The optimum ultrasound-assisted extraction conditions were as follows: ratio of liquid to solid, 60:1; ultrasound power, 135 W; ultrasound duration, 20 min. Under the optimum conditions, the antioxidant activities of the extract were increased by 95.55% and 64.46% by 2,2-diphenyl-1-picrylhydrazyl radical scavenging ability assay and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging ability assay, respectively, compared to those obtained by traditional maceration. The second-order kinetics model was employed to study the extraction process; it was found that ultrasound significantly accelerated the extraction of propolis and increased the maximum extraction volume of phenolic compounds. The qualitative and quantitative analysis of polyphenol compositions showed that ultrasound did not change the polyphenol types in the extract but it significantly improved the contents of various flavonoids and phenolic acids such as galangin, chrysin, pinocembrin, pinobanksin and isoferulic acid. Likewise, the FT-IR analysis indicated that the types of functional groups were similar in the two extracts. The SEM analysis revealed that the ultrasound-assisted extraction enhanced the contact areas between propolis and ethanol by breaking down the propolis particles and eroding the propolis surface.

Molecular Mechanisms of Oxidative Stress Relief by CAPE in ARPE-19 Cells

Caffeic acid phenylethyl ester (CAPE) is an antioxidative agent originally derived from propolis. Oxidative stress is a significant pathogenic factor in most retinal diseases. Our previous study revealed that CAPE suppresses mitochondrial ROS production in ARPE-19 cells by regulating UCP2. The present study explores the ability of CAPE to provide longer-term protection to RPE cells and the underlying signal pathways involved. ARPE-19 cells were given CAPE pretreatment followed by t-BHP stimulation. We used in situ live cell staining with CellROX and MitoSOX to measure ROS accumulation; Annexin V-FITC/PI assay to evaluate cell apoptosis; ZO-1 immunostaining to observe tight junction integrity in the cells; RNA-seq to analyze changes in gene expression; q-PCR to validate the RNA-seq data; and Western Blot to examine MAPK signal pathway activation. CAPE significantly reduced both cellular and mitochondria ROS overproduction, restored the loss of ZO-1 expression, and inhibited apoptosis induced by t-BHP stimulation. We also demonstrated that CAPE reverses the overexpression of immediate early genes (IEGs) and activation of the p38-MAPK/CREB signal pathway. Either genetic or chemical deletion of UCP2 largely abolished the protective effects of CAPE. CAPE restrained ROS generation and preserved the tight junction structure of ARPE-19 cells against oxidative stress-induced apoptosis. These effects were mediated via UCP2 regulation of p38/MAPK-CREB-IEGs pathway.

Anxiety and Metabolic Disorders: The Role of Botanicals

Anxiety and anxiety-related disorders are becoming more evident every day, affecting an increasing number of people around the world. Metabolic disorders are often associated with anxiety. Furthermore, anxiety branches into metabolic disorders by playing multiple roles as a cofactor, symptom, and comorbidity. Taken together, these considerations open the possibility of integrating the therapy of metabolic disorders with specific drugs for anxiety control. However, anxiolytic compounds often cause disabling effects in patients. The main goal could be to combine therapeutic protocols with compounds capable of reducing side effects while performing multiple beneficial effects. In this article we propose a group of bioactive ingredients called botanicals as a healthy supplement for the treatment of metabolic disorders related to anxiety.

Caffeic Acid Phenethyl Ester Loaded PEG-PLGA Nanoparticles Enhance Wound Healing in Diabetic Rats

Delayed wound healing is a serious complication of diabetes and a main reason for foot amputation. Caffeic acid phenethyl ester (CAPE) is a main active constituent of honeybee propolis with reported appealing pharmacological activities. In the current study, CAPE was loaded onto PEG-PLGA nanoparticles and showed a particle size of 198 ± 7.3 nm and polydispersity index of 0.43 ± 0.04. An in vivo study was performed to appraise the wound-healing activity of CAPE-loaded PEG-PLGA nanoparticles (CAPE-NPs) in diabetic rats. Wound closure was significantly accelerated in rats treated with CAPE-NPs. This was confirmed via histological examinations of skin tissues that indicated expedited healing and enhanced collagen deposition. This was accompanied by observed antioxidant activity as evidenced by the prevention of lipid peroxidation and the exhaustion of superoxide dismutase (SOD) and catalase (CAT) activities. In addition, CAPE-NPs showed superior anti-inflammatory activity as compared with the regular formula of CAPE, as they prevented the expression of interleukin-6 (IL-6) as well as tumor necrosis-alpha (TNF-α). The pro-collagen actions of CAPE-NPs were highlighted by the enhanced hyroxyproline content and up-regulation of Col 1A1 mRNA expression. Furthermore, the immunohistochemial assessment of skin tissues indicated that CAPE-NPs enhance proliferation and angiogenesis, as shown by the increased expression of transforming growth factor β1 (TGF-β1) and platelet-derived growth factor subunit B (PDGF-B). In conclusion, CAPE-loaded PEG-PLGA nanoparticles possess potent healing effects in diabetic wounds. This is mediated, at least partially, by its antioxidant, anti-inflammatory, and pro-collagen as well as angiogenic activities.

Caffeic Acid Phenethyl Ester Induces Vascular Endothelial Growth Factor Production and Inhibits CXCL10 Production in Human Dental Pulp Cells

The survival rate of root non-vital teeth is lower than that of vital teeth. Therefore, to preserve the dental pulp is very important. The vascular endothelial growth factor (VEGF) is the most potent angiogenic factor involved in the vitality of dental pulp including reparative dentin formation. Caffeic acid phenethyl ester (CAPE) is a physiologically active substance of propolis and has some bioactivities such as anti-inflammatory effects. However, there are no reports on the effects of CAPE on dental pulp inflammation. In this study, we investigated the effects of CAPE on VEGF and inflammatory cytokine production in human dental pulp cells (HDPCs) to apply CAPE to an ideal dental pulp protective agent. We found that CAPE induced VEGF production from HDPCs. Moreover, CAPE induced the phosphorylation of p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinases (ERK), and stress-activated protein kinase/c-Jun N-terminal kinase (SAP/JNK) in HDPCs. Furthermore, CAPE inhibited C-X-C motif chemokine ligand 10 (CXCL10) production in Pam3CSK4- and tumor necrosis factor-alpha (TNF-α)-stimulated HDPCs. In conclusion, these results suggest that CAPE might be useful as a novel biological material for vital pulp therapy by exerting the effects of VEGF production and anti-inflammatory activities.

Caffeic Acid Phenethyl Ester (CAPE) Inhibits Cross-Kingdom Biofilm Formation of Streptococcus mutans and Candida albicans

Streptococcus mutans and Candida albicans exhibit strong cariogenicity through cross-kingdom biofilm formation during the pathogenesis of dental caries. Caffeic acid phenethyl ester (CAPE), a natural compound, has potential antimicrobial effects on each species individually, but there are no reports of its effect on this dual-species biofilm. This study aimed to explore the effects of CAPE on cariogenic biofilm formation by S. mutans and C. albicans and the related mechanisms. The effect of CAPE on planktonic cell growth was investigated, and crystal violet staining, the anthrone-sulfuric acid assay and confocal laser scanning microscopy were used to evaluate biofilm formation. The structures of the formed biofilms were observed using scanning electron microscopy. To explain the antimicrobial effect of CAPE, quantitative real-time PCR (qRT-PCR) was applied to monitor the relative expression levels of cariogenic genes. Finally, the biocompatibility of CAPE in human oral keratinocytes (HOKs) was evaluated using the CCK-8 assay. The results showed that CAPE suppressed the growth, biofilm formation and extracellular polysaccharides (EPS) synthesis of C. albicans and S. mutans in the coculture system of the two species. The expression of the gtf gene was also suppressed by CAPE. The efficacy of CAPE was concentration dependent, and the compound exhibited acceptable biocompatibility. Our research lays the foundation for further study of the application of the natural compound CAPE as a potential antimicrobial agent to control dental caries-associated cross-kingdom biofilms. IMPORTANCE Severe dental caries is a multimicrobial infectious disease that is strongly induced by the cross-kingdom biofilm formed by S. mutans and C. albicans. This study aimed to investigate the potential of caffeic acid phenethyl ester (CAPE) as a natural product in the prevention of severe caries. This study clarified the inhibitory effect of CAPE on cariogenic biofilm formation and the control of cariogenic genes. It deepens our understanding of the synergistic cariogenic effect of S. mutans and C. albicans and provides a new perspective for the prevention and control of dental caries with CAPE. These findings may contribute to the development of CAPE as a promising antimicrobial agent targeting this caries-related cross-kingdom biofilm.

Polyphenols as Lung Cancer Chemopreventive Agents by Targeting microRNAs

Lung cancer is the second leading cause of cancer-related death worldwide. In recent decades, investigators have found that microRNAs, a group of non-coding RNAs, are abnormally expressed in lung cancer, and play important roles in the initiation and progression of lung cancer. These microRNAs have been used as biomarkers and potential therapeutic targets of lung cancer. Polyphenols are natural and bioactive chemicals that are synthesized by plants, and have promising anticancer effects against several kinds of cancer, including lung cancer. Recent studies identified that polyphenols exert their anticancer effects by regulating the expression levels of microRNAs in lung cancer. Targeting microRNAs using polyphenols may provide a novel strategy for the prevention and treatment of lung cancer. In this review, we reviewed the effects of polyphenols on oncogenic and tumor-suppressive microRNAs in lung cancer. We also reviewed and discussed the potential clinical application of polyphenol-regulated microRNAs in lung cancer treatment.

Metallothionein 2A with Antioxidant and Antitumor Activity Is Upregulated by Caffeic Acid Phenethyl Ester in Human Bladder Carcinoma Cells

Functions of metallothionein 2A (MT2A) in bladder cancer have not been extensively explored even though metallothioneins are regarded as modulators in several biological regulations including oxidation and cancerous development. We evaluated MT2A in bladder carcinoma cells in terms of the mechanisms of regulation and the underlying functions. MT2A overexpression not only downregulated endogenous ROS but also blocked ROS induced by H₂O₂. We used the annexin V-FITC apoptosis assay to determine the modulation of H₂O₂-induced cell apoptosis by MT2A expression. Results of immunoblot and reporter assays indicated that caffeic acid phenethyl ester (CAPE) treatment induced MT2A and heme oxygenase-1 (HO-1) expressions; moreover, the involvement of CAPE in either upregulation of the HO-1 expression or downregulation of endogenous ROS is MT2A dependent in bladder carcinoma cells. Knockdown of MT2A increased invasion and cell growth in vitro and in vivo, whereas ectopic overexpression of MT2A had the reverse effect in bladder carcinoma cells. Unlike bladder cancer tissues, the real-time reverse transcriptase-polymerase chain reaction (RT-qPCR) analysis showed a significant level of MT2A mRNA in the normal bladder tissues. Collectively, our results indicated that MT2A is acting as an antioxidant and also a tumor suppressor in human bladder carcinoma cells.

Curcumin and Related Compounds in Cancer Cells: New Avenues for Old Molecules

Curcumin and related compounds are known for the large spectrum of activities. The chemical features of these compounds are important for their biological effects with a key role for the thiol-reactive α−β unsaturated carbonyl groups. Curcumin derivatives may overcome the limitation of the bioavailability of the parent compound, while maintaining the key chemical features responsible for biological activities. Curcumin and related compounds show anti-viral, anti-fungal, anti-microbial and anti-tumor activities. The therapeutic effects of curcumin, used as a supplement in cancer therapy, have been documented in various cancer types, in which inhibition of cell growth and survival pathways, induction of apoptosis and other cell death pathways have been reported. Curcumin-induced apoptosis has been linked both to the intrinsic and extrinsic apoptotic pathways. Necroptosis has also been involved in curcumin-induced toxicity. Among curcumin-induced effects, ferroptosis has also been described. The mechanism of curcumin toxicity can be triggered by reactive oxygen species-mediated endoplasmic reticulum stress. Curcumin targets have been identified in the context of the ubiquitin-proteasome system with evidence of inhibition of the proteasome proteolytic activities and cellular deubiquitinases. Curcumin has recently been shown to act on the tumor microenvironment with effects on cancer-associated fibroblasts and immune cells. The related product caffeic acid phenethyl ester has shown promising preclinical results with an effect on the inflammatory microenvironment. Here, we review the mechanisms underlying curcumin and derivatives toxicity towards cancer cells with particular emphasis on cell death pathways and the ubiquitin-proteasome system.

Copper Porphyrin-catalyzed C(sp3)-H Activation via Cross Dehydrogenative Coupling: Facile Transformation of Aldehydes to Esters

Copper porphyrin-catalyzed alkane C−H bond functionalization with aldehydes via cross dehydrogenative coupling (CDC) using DTBP oxidant has been firstly described in non-solvents or non-additives system. Different aryl/heteroaryl-carboxilic esters were obtained in good to excellent yields depending on the aldehyde derivatives. This CDC reaction catalyzed by copper porphyrin has the advantages of shorter reaction time, lower reaction temperature and catalyst loading as well as the aerobic reaction atmosphere.

Evaluation of the Healing Effect of Ointments Based on Bee Products on Cutaneous Lesions in Wistar Rats

The wound-healing capacity of ointments based on bee products was investigated in vivo on three experimental models of incision, excision and heat burn. For this purpose, four ointments were prepared with propolis, honey, apilarnil (drone brood homogenate) and a mixture of these three apitherapy products. The ointments were applied topically for 21 days. Clinical and macroscopic evaluation was performed throughout the experiment, with the recording of the re-epithelialization period and determination of the wound contraction rate on days 6 and 9. The histopathological examination was performed on days 1, 3, 12 and 21 of the treatment. The topical formulations were also characterized from a rheological point of view in order to verify their stability. HPLC analysis of propolis revealed the presence of phenolic compounds, particularly ferulic acid and p-coumaric which were found in high amounts. All ointments had beneficial effects on wound contraction and the re-epithelialization period, but the most significant result, both macroscopically and especially in terms of histological architecture, was presented by the ointment that contains all three apitherapy products, due to their synergistic effect.

Role of inflammation and oxidative stress in tissue damage associated with cystic fibrosis: CAPE as a future therapeutic strategy

Cystic fibrosis (CF) is an autosomal recessive disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, responsible for the synthesis of the CFTR protein, a chloride channel. The gene has approximately 2000 known mutations and all of them affect in some degree the protein function, which makes the pathophysiological manifestations to be multisystemic, mainly affecting the respiratory, gastrointestinal, endocrine, and reproductive tracts. Currently, the treatment of the disease is restricted to controlling symptoms and, more recently, a group of drugs that act directly on the defective protein, known as CFTR modulators, was developed. However, their high cost and difficult access mean that their use is still very restricted. It is important to search for safe and low-cost alternative therapies for CF and, in this context, natural compounds and, mainly, caffeic acid phenethyl ester (CAPE) appear as promising strategies to assist in the treatment of the disease. CAPE is a compound derived from propolis extracts that has antioxidant and anti-inflammatory activities, covering important aspects of the pathophysiology of CF, which points to the possible benefit of its use in the disease treatment. To date, no studies have effectively tested CAPE for CF and, therefore, we intend with this review to elucidate the role of inflammation and oxidative stress for tissue damage seen in CF, associating them with CAPE actions and its pharmacologically active derivatives. In this way, we offer a theoretical basis for conducting preclinical and clinical studies relating the use of this molecule to CF.

The Anti-Biofilm Efficacy of Caffeic Acid Phenethyl Ester (CAPE) In Vitro and a Murine Model of Oral Candidiasis

Candida albicans is the main fungal species associated with the development of oral candidiasis. Currently, therapeutic options for these infections are limited by the adverse effects of antifungal drugs and by the emergence of drug resistant strains. Thus, the development of new antifungal agents is needed for the prevention and treatment of oral Candida infections. Caffeic acid phenethyl ester (CAPE) is a natural compound from propolis polyphenolic groups that exhibits many pharmacological properties. In this study, we investigated whether CAPE can have antifungal and immunomodulatory effects on oral candidiasis. Preliminary tests to assess the antifungal activity of CAPE were performed using the Minimum Inhibitory Concentration (MIC) assay that demonstrated inhibition in a range from 16 to 32 μg/mL, confirming its antifungal activity on several C. albicans strains isolated from the oral cavity. Subsequently, we analyzed Candida spp biofilms formed in vitro, in which CAPE treatment at 5 x MIC caused a reduction of 68.5% in the total biomass and ~2.60 Log in the viable cell count (CFU/mL) in relation to the untreated biofilm (p<0.0001). Next, RNA was extracted from untreated and CAPE-treated biofilms and analyzed by real-time qPCR. A series of genes analyzed (ALS1, ECE1, EPA1, HWP1, YWP1, BCR1, BGR1, CPH1, EFG1, NDT80, ROB1, TEC1, UME6, SAP2, SAP5, PBL2, and LIP9) were downregulated by CAPE compared to the untreated control group (p<0.0001). In in vivo studies using Galleria mellonella, the treatment with CAPE prolonged survival of larvae infected by C. albicans by 44.5% (p < 0.05) and accompanied by a 2.07-fold increase in the number of hemocytes. Flow cytometry revealed the most prominent increases were in types P2 and P3 hemocytes, granular cells, which phagocytize pathogens. In addition, CAPE treatment decreased the fungal load in the hemolymph and stimulated the expression of antifungal peptide genes such as galiomicin and gallerimycin. The antifungal and immunomodulatory activities observed in G. mellonella were extended to a murine model of oral candidiasis, in which CAPE decreased the levels of C. albicans colonization (~2 log CFU/mL) in relation to the untreated control group. In addition, CAPE treatment significantly reduced pseudomembranous lesions, invasion of hyphae on epithelium surfaces, tissue damage and inflammatory infiltrate (p < 0.05). CAPE was also able to increase the expression of β-defensin 3 compared to the infected and untreated group by 3.91-fold (p < 0.0001). Taken together, these results show that CAPE has both antifungal and immunomodulatory effects, making it a promising natural antifungal agent for the treatment and prevention of candidiasis and shows impact to oral candidiasis.

Propolis Extract and Its Bioactive Compounds-From Traditional to Modern Extraction Technologies

Propolis is a honeybee product known for its antioxidant, anti-inflammatory, anticancer, and antimicrobial effects. It is rich in bioactive molecules whose content varies depending on the botanical and geographical origin of propolis. These bioactive molecules have been studied individually and as a part of propolis extracts, as they can be used as representative markers for propolis standardization. Here, we compare the pharmacological effects of representative polyphenols and whole propolis extracts. Based on the literature data, polyphenols and extracts act by suppressing similar targets, from pro-inflammatory TNF/NF-κB to the pro-proliferative MAPK/ERK pathway. In addition, they activate similar antioxidant mechanisms of action, like Nrf2-ARE intracellular antioxidant pathway, and they all have antimicrobial activity. These similarities do not imply that we should attribute the action of propolis solely to the most representative compounds. Moreover, its pharmacological effects will depend on the efficacy of these compounds’ extraction. Thus, we also give an overview of different propolis extraction technologies, from traditional to modern ones, which are environmentally friendlier. These technologies belong to an open research area that needs further effective solutions in terms of well-standardized liquid and solid extracts, which would be reliable in their pharmacological effects, environmentally friendly, and sustainable for production.